The present application relates to complementary metal oxide semiconductor (CMOS) transistors, and more specifically to CMOS vertical transistors.
CMOS is used for constructing integrated circuits. CMOS technology can be used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. CMOS designs commonly use complementary and symmetrical pairs of p-type and n-type metal oxide semiconductor field effect transistors (MOSFETs) for logic functions.
Vertical transistors are attractive candidates for 5 nm node and beyond due to better density scaling. Vertical transistors also allow relaxed gate lengths for better control of electrostatics. However, there remains a need for improved methods and structures for fabrication of CMOS vertical transistors with tight pitch, which results in a high device packing density.